Struktur und Eigenschaften einer hochfesten sprühkompaktierten Aluminiumlegierung

Structure and Properties of a High Strength Spray-Deposited Aluminum Alloy A 7XXX series high strength aluminium alloy was produced by spray-deposition via the Osprey process. This alloy, designated A1Zn11MgCu, exhibits an excellent combination of fracture toughness and strength in both the peak-aged T6 temper and the overaged T7 temper. The yield strength and fracture toughness at room temperature are in the T6 temper 700 MPa and about 40 MPa√m, and in the T7 temper 500 MPa and 75 MPa√m, respectively. The exceptional high fracture toughness is attributed to the absence of coarse constituents and oxides. The microstructure is homogeneous, free of segregation and has a fine grain size. The hardening precipitates in the T6 temper are mainly η′, and the T7 temper they are η (MgZn₂), resulting in a different fracture behavior: in the T6 temper the fracture mode is micro-shearing and in the T7 temper fracture mode is ductile failure.